BIDDEFORD, Maine — Maine’s only Market Basket is laying off 300 part-time workers as protests over the supermarket’s leadership continue.

Micum McIntire, store director of the Biddeford Market Basket, said his store will lay off 300 part-timers, which he said, takes effect “right now.”

“I am not able to use any part-timers at this time,” McIntire said, adding that there are about 20,000 part-timers throughout the Market Basket chain. “Hopefully it’s temporary. Obviously we’re hoping this thing turns around so we can get back to normalcy.”

The staffing reduction was ordered by the company’s co-CEOs Felicia Thornton and James Gooch, because of the customer boycott that has caused sales to plummet by 90 percent at many stores.

Story continues below advertisement.

The standoff is in its third week as workers and customers continue to demand the return of ousted Market Basket CEO Arthur T. Demoulas, who has made an offer to purchase the remaining 50.5 percent shares of the company owned by his rival cousin, Arthur S. Demoulas, and his side of the family. The two sides have fought for years over the company’s direction, but employees have remained loyal to Arthur T. Demoulas, who was fired in June by the company’s board controlled by Arthur S Demoulas.

“As we are all aware, our store sale volumes are substantially reduced from standard levels. As has always been our practice, your role as store directors requires you to manage payroll as one of your many responsibilities. This means you need to schedule staff levels necessary to serve your current customer base and maintain store conditions,” according to the memo from Thornton and Gooch.